Procedures for replacement of all or part of a patient's joint have been in existence for a number of years. The current procedures generally require large incisions to be made through the skin and underlying tissue of the patient to allow the surgeon to access and see the joint while the surgery is being carried out.
For example to carry out hip replacement or hip resurfacing surgery an incision approximately 25-30 cm must be made through the skin and underlying tissue. Such an incision allows good visibility of the joint and the surgery can therefore be carried out using the naked eye. Furthermore current surgical devices such as reaming devices, impactors and pushers used in surgery such as hip replacement and his resurfacing require good access to the joint which is provided by a large incision.
Reaming devices generally comprise a rotating cutting portion situated at the end of an elongate drive shaft and connected to a power source. Reaming devices are used in hip replacement and hip resurfacing surgery to remove bone tissue from the acetabulum before a prosthetic acetabular cup is fitted. Pushers and impactors are used in the fitting or prosthetic joint components such as acetabular cups to the acetabulum.
Posterior access to a hip joint is usual during surgery and, as a result to obtain sufficient access to the joint a large amount of muscle tissue must be divided, cut through or separated from the bone to which it is anchored. This division or separation of the muscle allows the femoral head to be moved away from the acetabulum to allow access to the acetabulum, for example with a reaming device, or to allow removal of the femoral head. The division or separation of muscle is essential in the current methods for resurfacing a hip joint where the femoral head is not removed and access to the joint is therefore reduced.
Muscles such as the gluteus maximus and gluteus medius are usually cut through, divided or separated from the bone to which they are attached during hip surgery as are the tensor fascia lata and the ilio-tibial tract. Although the muscles do repair themselves following surgery the recovery period, in and out of hospital, and the amount of physiotherapy required is extensive. It is also possible that the muscles may never regain the strength they had before surgery. Furthermore cutting through muscles can lead to a significant loss of blood and the patient may require a blood transfusion.